Arrangements storing different versions of a set of data in separate memory areas and method for updating a set of data in a memory

Abstract

Computer-readable medium storing a data structure for supporting persistant storage of a set of data, the data structure including: (a) at least an oldest version of the set of data in a first memory area the first memory area including at least one first tag for uniquely identifying the oldest version, and (b) at least a most recently updated version of the set of data in a second, distinct memory area, the second memory area including at least one second tag for uniquely identifying the most recently updated version. The invention also relates to a computer arrangement including a processor and such a computer-readable medium, as well as to a method of updating sets of data having such tagged-data structures.

The invention claimed is: 
     
       1. A method for ensuring at least one valid version of a software object is stored in a memory device, comprising:
 incrementally storing versions of the software object in memory locations in the memory device, including creating each version of the software object based on a copy of a previous verified version of the software object stored in the memory device, each version of the software object being created using a second memory device; 
 verifying each version as it is stored in the memory device; 
 receiving a request to access the software object; and 
 using a latest verified version of the software object for processing the access request. 
 
     
     
       2. The method of  claim 1 , wherein incrementally storing versions of the software object includes:
 storing in each memory location a tag identifying the version of the software object stored in each memory location. 
 
     
     
       3. The method of  claim 1 , wherein verifying includes deallocating a memory location storing an oldest version of the software object when at least one verified version of the software object is stored in a memory location. 
     
     
       4. The method of  claim 2 , wherein each tag is stored after storing the identified version of the software object. 
     
     
       5. The method of  claim 1 , wherein the method is performed by a processing system in a smart card. 
     
     
       6. The method of  claim 2 , wherein each memory location includes one or more portions of the memory device and wherein each stored version of the software object is associated with a respective tag stored in each of the one or more portions of the memory. 
     
     
       7. The method of  claim 6 , wherein the one or more portions of the memory device includes at least one of consecutive memory portions and non-consecutive memory portions. 
     
     
       8. The method of  claim 2 , wherein verifying includes:
 verifying each version as it is stored in the memory device using the tag for the respective version of the software object. 
 
     
     
       9. The method of  claim 8 , wherein verifying includes:
 using the tags to determine whether a respective version of the software object is correctly stored in the appropriate respective memory location. 
 
     
     
       10. The method of  claim 1 , wherein the second memory device is a volatile memory device and the memory device is a non-volatile memory device. 
     
     
       11. The method of  claim 1 , wherein verifying includes:
 detecting an event that interrupts the storing of a current version of the software object in a respective memory location; and 
 determining that the current version is unverified based on the detected event. 
 
     
     
       12. The method of  claim 11 , wherein the latest verified version of the software object is used to create the current version of the software object. 
     
     
       13. A system for ensuring at least one valid version of a software object is stored in a memory device, comprising:
 means for storing versions of the software object in respective memory locations in the memory device, including creating each version of the software object based on a copy of a previous verified version of the software object stored in the memory device, each version of the software object being created using a second memory device; 
 means for verifying each version as it is stored in the memory device; 
 means for receiving a request to access the software object; and 
 means for using a latest verified version of the software object for processing the access request. 
 
     
     
       14. The system of  claim 13 , wherein the means for storing versions of the software object includes:
 means for storing in each memory location a tag identifying the version of the software object stored in each respective memory location. 
 
     
     
       15. The system of  claim 13 , wherein the means for verifying includes means for deallocating a memory location storing an oldest version of the software object when at least one verified version of the software object is stored in a memory location. 
     
     
       16. The system of  claim 13 , wherein each tag is stored after storing the identified version of the software object. 
     
     
       17. The system of  claim 14 , wherein the system is a smart card. 
     
     
       18. The system of  claim 14 , wherein each memory location includes one or more portions of the memory device and wherein each stored version of the software object is associated with a respective tag stored in each of the one or more portions of the memory. 
     
     
       19. The system of  claim 18 , wherein the one or more portions of the memory device includes at least one of consecutive memory portions and non-consecutive memory portions. 
     
     
       20. The system of  claim 14 , wherein the means for verifying includes:
 means for verifying each version as it is stored in the memory device using the tag for the respective version of the software object. 
 
     
     
       21. The system of  claim 20 , wherein the means for verifying includes:
 means for using the tags to determine whether a respective version of the software object is correctly stored in the appropriate respective memory location. 
 
     
     
       22. The system of  claim 13 , wherein the second memory device is a volatile memory device and the memory device is a non-volatile memory device. 
     
     
       23. The system of  claim 13 , wherein the means for verifying includes:
 means for detecting an event that interrupts the storing of a current version of the software object in a respective memory location; and 
 means for determining that the current version is unverified based on the detected event. 
 
     
     
       24. The system of  claim 23 , wherein the latest verified version of the software object is used to create the current version of the software object.